Closure lid with a pressure-controlled or temperature-controlled directional control valve for an expansion tank and cooling system of an internal combustion engine

Abstract

A closure lid for an expansion tank of a cooling system of an internal combustion engine has integrated therein a directional control valve that decouples the expansion tank from the cooling circuit by pressure control or temperature control and integrates the expansion tank again into the cooling circuit after the internal combustion engine has reached its operating temperature.

What is claimed is: 
     
         1 .- 9 . (canceled) 
     
     
         10 . A closure lid for an expansion tank of a cooling system of an internal combustion engine, the closure lid comprising:
 a housing;   a directional control valve integrated in the housing;   the directional control valve having an outlet connected to the expansion tank;   the directional control valve having an inlet connected to a bypass line;   the directional control valve adapted to open and close by pressure control or temperature control.   
     
     
         11 . The closure lid according to  claim 10 , wherein the housing has a section delimiting in annular space, wherein the housing has a recess in which the directional control valve is disposed, and wherein a hydraulic connection exists between the recess and the section of the housing delimiting the annular space. 
     
     
         12 . The closure lid according to  claim 11 , wherein a valve seat of the directional control valve is formed or arranged in the recess. 
     
     
         13 . The closure lid according to  claim 12 , wherein the directional control valve comprises a valve member and the valve member interacts with the valve seat. 
     
     
         14 . The closure lid according to  claim 13 , wherein the valve member is spring-loaded or is actuated by a bimetal. 
     
     
         15 . The closure lid according to  claim 14 , further comprising a pressure spring that spring-loads the valve member, wherein the pressure spring is arranged between the valve member and a spring plate that is attached at least indirectly to the housing. 
     
     
         16 . The closure lid according to  claim 13 , wherein the valve seat is a plate seat. 
     
     
         17 . The closure lid according to  claim 10 , wherein a blocking function of the directional control valve depends on a screw-in depth of the closure lid in a socket of the expansion tank. 
     
     
         18 . A cooling circuit for an internal combustion engine comprising an external cooling agent circuit and an expansion tank, wherein the external cooling agent circuit has an inlet and a return line and supplies waste heat of the internal combustion engine to a cooler of the cooling agent circuit, wherein the expansion tank is connected by a bypass line and by an outlet hydraulically to the cooling agent circuit, wherein the expansion tank has a socket and a closure lid embodied according to  claim 10  and adapted to close off the socket.